Please Point

Fri Mar 15, 2013 7:17 pm

Haven't been here in awhile,... Had a professional rebuild the carb, and she fired up in 4 seconds after 18 mths. I need to know how to set the govenor, I am so far over the top end of rpms, I've got to choke to slow down...

Need to plow the driveway, and it's good to hear the Cub run, even if it's only for a few seconds,.... too fast.

Re: Please Point

Fri Mar 15, 2013 8:00 pm

In this case, the first thing I'd check is that the throttle and choke linkages are attached in the right places, not swapped with each other. Then adjust the governor/carb linkage as Bill V suggested.

Re: Please Point

Fri Mar 15, 2013 8:27 pm

Jim Becker wrote:In this case, the first thing I'd check is that the throttle and choke linkages are attached in the right places, not swapped with each other. Then adjust the governor/carb linkage as Bill V suggested.

Re: Please Point

Fri Mar 15, 2013 8:32 pm

govenor shaft to the upfeed to manifold, choke to air cleaner..??

Re: Please Point

Fri Mar 15, 2013 8:36 pm

yes that is right. Make sure the governor linkages are not binding anywhere. also make sure the Idle screw is set . And is it an IH carb or a Zenith? the zenith will bind in the manifold if it is an older cub unless you use at lest 2 gaskets

Re: Please Point

Fri Mar 15, 2013 8:45 pm

this was the original that I had Case rebuild with an incredibly valued OEM kit. Years ago I had done a Tractor supply kit, (not too well) and adjusted the timing by turning the distributor.... This thing sounds like it's on rocket fuel, and an RPM that's outrageous... Mind it hasn't turned over in a very long time..

Re: Please Point

Sat Mar 16, 2013 7:34 am

With the engine off and the throttle lever near idle position, you should be able to move the carb. linkage, freely, through it's full travel. Make sure you can easily move it fully to the idle position. If you can't, there's something binding it somewhere.

Re: Please Point

Sat Mar 16, 2013 7:52 am

Jim Becker wrote:In this case, the first thing I'd check is that the throttle and choke linkages are attached in the right places, not swapped with each other. Then adjust the governor/carb linkage as Bill V suggested.

Grandfather's Cub wrote:This thing sounds like it's on rocket fuel, and an RPM that's outrageous... Mind it hasn't turned over in a very long time..

Remove the hose from the air cleaner to carburetor. Pull the choke lever on the dash. Check to see if the carburetor choke valve plate in the carburetor throat is closed. Push the choke lever on the dash in and see if the choke valve plate opens.

The described uncontrolled RPMs is a symptom of having the choke and governor linkage on the back side of the carburetor reversed.

Re: Please Point

Sat Mar 16, 2013 6:56 pm

Tomorrow the govenor comes off. I've adjusted likages moving the govenor arm toward the fan and i think i've slowed the rpm's slightly compared to towards the carb, but I can't get it nearly far forward enough. This thing has no response to input from the throttle, or manual movement of the throttle rod to the govenor. What else can simulate reversed linkages? It really is amazing how easy it starts, and if rpm's were good, I'd be moving some dirt.....

Re: Please Point

Thu Mar 21, 2013 1:30 pm

Went to the IH Case dealer who rebuilt the carb, and one gent said I should be able to control RPMs with the carb by changing the govenor linkage when it is disconnected.

With ALL linkages disconnected, I can not get the RPM's low enough with the carb at idle, other than the choke.

Which comes first, The Carb or the Govenor...?

Laying an egg...

Re: Please Point

Thu Mar 21, 2013 2:21 pm

If you have the linkage between governor and carb disconnected, and you still cannot slow the rpms down by manually closing the throttle plate, I believe there is some problem within the carb. I wonder if you have the wrong size main metering jet?

Re: Please Point

Thu Mar 21, 2013 3:20 pm

Have you backed out the idle speed screw on the throttle plate arm? If that doesn't fix it, the throttle plate wasn't properly centered in the throat when it was attached to the throttle shaft.

Those are the only 2 possible explanations for the symptoms you describe.

Re: Please Point

Fri Mar 22, 2013 6:23 am

I agree, Jim, I've encountered throttle plate issues a number of times. The fix is to back off the idle speed adjusting screw, loosen the two screws holding the throttle plate, hold the throttle shaft firmly closed while re-tightening the screws. Then you can adjust the speed screw to get a small gap at the edge of the throttle before re-installing the carb. If you can't control engine speed with the governor out of the picture, it has to be an issue with the throttle plate, either not centered, damaged, or getting hung up on the gasket or manifold.

Re: Please Point

Fri Mar 22, 2013 7:40 am

Thanks Gents!!!

I thought letting someone who knew what they were doing, rebuild the carburetor was the way to go I am so glad I didn't pull the govenor. Thanks again. I love this place!